The takeaway
Clean Harbors Inc shows a moderate seasonal pattern over 10 years of data — strongest in July (+3.7%) and softest in October (−1.5%).
Right now
In July, the stock has risen 90% of years, averaging +3.7%, about +1.6 pts better than the S&P 500.
The full picture
Clean Harbors Inc's most dependable month has been July, higher in 9 of 10 years; October has been its least reliable, up just 30% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in November (+4.4 pts); it has trailed the market most in December (−2.8 pts).
“vs S&P” is Clean Harbors Inc’s average for a month minus the S&P 500’s average for that same month — isolating Clean Harbors Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, July has closed higher 100% of the time versus 90% across the last 10 years — the pattern is holding.
Figures are the typical (median) July return and how often it rose — the last 5 years versus the last 10(the heatmap’s default window). This verdict stays anchored to that 10-year window even if you zoom the chart, so it never disagrees with the badges above.
In plain English
Dependability is the through-line here. July stands out, higher in 9 of 10 Julys, but it heads a clutch of months that pull the year reliably upward.
A typical July brings +2.5%, a shade under the +3.7% average. It is also the calendar's calmest month, its returns swinging least from year to year (a 3.7% spread), and even its worst July in 10 years lost only 2.2% — the gentlest downside anywhere on its calendar. Crucially, the gain is the stock's own rather than a rising tide's: July has cleared the S&P 500 by +1.6 points above the index. That consistency sets it apart from the field, where the average stock manages July only about 61% of the time.
The lift is near-universal — strength runs through almost every month of the year, not one window. At the other end of the calendar, October has been the soft spot — the weakest of 2 months that average a loss (−1.5%), and the edge isn't year-round — the stock has trailed the S&P 500 in December and October. Its roughest month on record was a −29.4% March in 2020 — a reminder of how hard even a seasonal name can fall.
July has now closed higher 9 years running. Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
The takeaway is less about when to buy than what to expect: July aside, the stock's months offer little reliable tilt.
Short answers on the stock's best month (July), its worst (October), and whether it really trades seasonally.
Yes, to a moderate degree. Since 2016 its best month (July, +3.7%) has run well ahead of its worst (October, −1.5%) — the heatmap above shows how steady that gap has been year to year.
July has been the strongest, averaging +3.7% and closing higher in 9 of 10 years since 2016.
It's the weakest, averaging −1.5% — historically a soft spot, though it still varies from year to year.
Explore
These names have the strongest July track records on record — a starting point for comparison.
Before you trade